DESCRIPTION: (Applicant's Abstract) The purpose of this four-year study, entitled "Pathways to High-Risk Drug Abuse Among Urban Youth," is to identify critical factors responsible for the transition from gateway poly-drug use (defined as use of alcohol/marijuana and one other drug in the past month) to "hard" drug use (defined here as weekly heroin and/or cocaine sniffing, smoking, or injection) and the associated health risks among multiethnic inner city mature minors and young adults (ages 16-24). The study is important because the transition to hard drug use and associated exposure to HIV is known to occur during this time and because preventing the transition will simultaneously reduce the risk of HIV infection in this age cohort. Both national and local studies, including those conducted by the Institute for Community Research and the Hispanic Health Council in Hartford with two populations (in-school youth at risk for substance abuse and other risks; and injection drug and crack cocaine users), have not yet reached very high risk youth in the target age group, especially in smaller urban areas. The study combines a longitudinal epidemiologic approach to understanding the natural history of progression to hard drug use, with network ethnography to examine the role of social networks in influencing drug use transitions. The aims of the study are to: a) conduct exploratory ethnographic research to identify drug use histories and contexts; validate and pilot epidemiological and network instruments; and identify index individuals for network study in target neighborhoods (Stage 1, Year 1); b) conduct a panel study with 400 high risk youth at two points in time 18 months apart to identify the relative contributions of individual vulnerability and personal and macro-network characteristics to the transition from gateway polydrug use to cocaine/heroin use (Stage 2, Months 13-40); c) use the results to promote focus group discussions around appropriate approaches to outreach and intervention with hidden populations of high risk youth (Stage 3, Months 41-45); and d) generate a manual outlining ethical approaches to ethnoepidemiological research with mature minors and young adults involved in dangerous or illegal activity, through annual ethics symposia and collection and coding of observations, interviews and discussion. Results will be used to frame strategies for preventing hard drug use and HIV transmission in the target population and for advancing the discussion of ethical issues in multi- method drug and AIDS research with mature minors and young adults.